1. Field of the Invention
The present invention relates to a data communication apparatus such as a facsimile device, and more particularly to a data communication apparatus which accommodate a plurality of channels or communication lines and effects multi-address transmission to a plurality of destinations by using those channels or communication lines in parallel.
2. Related Background Art
An ISDN (integrated service digital network) has been known as a line having a plurality of channels. A basic interface of a user network of the ISDN line is that one line comprises two information channels (B channels) and one control channel (D channel). A facsimile terminal uses the two B channels of the three communication channels to effect the multi-address transmission to two destinations.
In the prior art, however, since the two information channels are simultaneously used, there is no vacant channel during the multi-address transmission and other communication operations such as reception and prioritized transmission are not accepted.